Dual contact probe assembly for testing integrated circuits

Abstract

An assembly for making electrical connections to unpackaged integrated circuits using dual contact probes. The probes are said to be dual contact because they contact both the integrated device under test and the testing circuit. The probes have two tips. One tip is located at the end of each leg of the "U"-shaped probe. In operation, the probes are oriented with the legs of the probes extending horizontally and the tips pointing up and down, contacting the IC under test and the testing circuit. The probes are each made of a single piece of metal, and so provide an electrical connection between the IC and testing circuit. Flexing in the legs provides springiness for assuring good contact. The probes are mounted on a rigid block that is rigidly connected to the testing circuit and IC under test. Alignment plates are used to accurately position the probes. The plates can be horizontal or vertical and they have holes or slots that engage parts of the probes. The holes and slots are placed to provide proper positioning of the probes.

What is claimed is: 
     
       1. A circuit testing mechanism for simultaneously contacting contact pads of a DUT and maintaining contact with contact pads of a testing circuit by using dual-contact probes, said dual-contact probes having a mounting section from which extends a first beam terminating in a first tip portion and a second beam terminating in a second tip portion, said circuit testing mechanism comprising: a) a mounting block for fixedly mounting said dual-contact probes by said mounting section such that said first beam and said second beam experience independent flexure under the application of a contact force to said tip portions, and such that said first beam and said second beam extend away from said mounting block;   b) a means for positioning said testing circuit such that said the contact pads of said testing circuit maintain contact with said first tip of said dual-contact probes; and   c) a means for driving said DUT such that the contact pads of said DUT come in contact with said second tip of said dual-contact probes.   
     
     
       2. The circuit testing mechanism of claim 1 wherein said dual-contact probes are substantially U-shaped, said first beam and said second beam constituting the legs of the U-shape. 
     
     
       3. The circuit testing mechanism of claim 1 further comprising a mounting block tongue. 
     
     
       4. The circuit testing mechanism of claim 1 further comprising at least one alignment plate. 
     
     
       5. The circuit testing mechanism of claim 1 wherein at least one of said alignment plates is oriented vertically. 
     
     
       6. The circuit testing mechanism of claim 1 wherein at least one of said alignment plates is oriented horizontally. 
     
     
       7. The circuit testing mechanism of claim 1 wherein at least one of said alignment plates is removable. 
     
     
       8. The circuit testing mechanism of claim 1 wherein said alignment plate has vertical slots and said first tip portion and said second tip portion have heels for placing into said vertical slots. 
     
     
       9. The circuit testing mechanism of claim 8 wherein said heels have a sloped edge for wedging into said vertical slots. 
     
     
       10. The circuit testing mechanism of claim 1 wherein said alignment plate has horizontal slots for receiving lateral locator plates. 
     
     
       11. The circuit testing mechanism of claim 10 wherein said mounting section of said dual-contact probes has a slit for engaging said lateral locator plates. 
     
     
       12. The circuit testing mechanism of claim 10 wherein said lateral locator plates extend in-between mounting sections of said dual-contact probes. 
     
     
       13. The circuit testing mechanism of claim 1 wherein said dual-contact probes have a through-hole in said mounting section for receiving a pin to stabilize said dual-contact probes. 
     
     
       14. The circuit testing mechanism of claim 1 further comprising epoxy for mounting said dual-contact probes on said support block. 
     
     
       15. The circuit testing mechanism of claim 1 further comprising a clamping device for removably securing said testing circuit. 
     
     
       16. The circuit testing mechanism of claim 15 wherein said clamping device is affixed on said mounting block. 
     
     
       17. The circuit testing mechanism of claim 1 wherein at least one of said alignment plates is a dual layer alignment plate.